Multivariate analysis review

Attendance: Catherine Johnson, Benoit Casault, Emily Chisholm

Meeting minutes

  • EC will take notes from today and from BC’s email (May 12) and incorporate them into Reid’s methodology document

    • Some structural reorganization will be done
    • Draft will be reviewed by CJ and BC
  • EC and BC will work to update this gitHub repo to include the latest versions of all scripts and data

  • Each metric has now been calculated 3 times, once by Dan Reed, then by Reid Steele, then by BC

  • BC plotted a comparison of all 3 outputs for comparison

  • Plots will be updated to remove jitter, plotting different users with low opacity shapes to distinguish with precision (BC)

  • Group went over each plot individually to identify issues

Physical Variables

Physical variable comparison

Physical variable comparison

  • AMO

    • DR had used annual values
    • RS and BC used monthly values
    • All three outputs appear to have significant differences
    • EC will investigate differences using other sources for AMO (literature, SART, Res Docs) - BC will send data to facillitate
  • Bottom temp 4V includes both 4Vs and 4Vn

  • Ice volume

    • BC and RS used updated data source
    • Some small differences between DR older data
    • will maintain newer data set moving forward
  • NAO

    • DR used data from Roger Pettipas (pressure)
    • RS and BC used Peter Galbraith’s anomoly data
    • difference in scales makes plot difficult to interpret
    • EC will create scatter plot to compare relationship, eg interannual variability, to ensure data is similar despite scale
  • SST

    • difference in data sources between DR and BC/RS
    • RS and BC used Peter Galbraith’s reprocessed data
    • RS combined 4Vs and 4Vn
    • BC used only 4Vs
    • DR analysis was performed before 4V s/n distinction
    • moving forward will use 4Vs
  • stratification

    • RS used only HL2 data (error)
    • BC and DR used all SS data
    • EC will ensure all SS data is incorporated in package
  • Bottom temperature note

    • 4V and 4W have no 2018 data
    • RS interpolated on BC recommendation using 4X scale value
    • EC will investigate whether this is necessary in PCA
    • CJ will consider best interpolation scheme
    • Incorporate note in future versions of analysis to ensure readers are aware of interpolation

Phenology Variables

Phenology variable comparison

Phenology variable comparison

Phenology variable comparison

Phenology variable comparison

  • Zooplankton peaks
    • BC could not find DR code
    • BC followed methods presented in paper (PCA -> LOESS fit)
    • DR performed a sepearte analysis (PCA) on Calanus stages to get exact timing
    • CJ will look back on DR code for stage abundance PCA
  • BioMass Max
    • RS method is wrong, uses abundance not biomass
    • This requires more investigation to confirm
  • Cfin I + II + III
    • good agreement between DR and BC
    • BC had bug with 1999 and 2007 values to be resolved
  • Cfin HL2
    • agreement between DR and BC
  • Note:
    • Dan cleaned up a lot of scripts before leaving, he may have left out some interim steps and data products
    • Ideally would use original DR code, but some cases where BC had to rewrite might be necessary
    • CJ will investigate and look for original code
    • If it can not be found may require follow up with DR
  • Ice Area
    • BC and RS used new data provided by Peter Galbraith
    • DR used data from Roger Pettipas
    • will maintain new data source (PG)
  • Ice end day
    • All OK
  • Bloom parameters
    • some reprocessing of data may have been done in between DR analysis and BC/RS analysis
    • BC will check and follwo up
    • some differences in anomoly calculations between BC and DR
    • may be due to DR lack of reference period in calculations
  • SST warming
    • All OK
    • small differences from DR due to processing

Zooplankton variables

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

Zooplankton Variable Comparisons

  • Mostly good agreement between all sources due to least amount of data reprocessing/ adjustment

  • Differences in CSS

    • Dr and BC used distinct vars for HL and HL2
    • RS did not use any distinction
    • EC will investigate how this is handled in PCA to ensure consistency
  • Metridia

    • Some small differences due to data correction
    • note that pre 2008 ‘Metridia’ maintains zero value, this is likely due to identification methods
    • EC will investigate if Metridia (without species designation) is included in PCA
      • similar issue in Oithona and centropages, less extreme
      • CJ will also investigate raw data
  • Reference period

    • BC will double check that the same reference period was used throughout (should be 1999-2015)